1 / 11

Chapter 19-20

Chapter 19-20. Populations and Species Interactions. Properties of a Population. Population – a group of organisms that belong to the same species and live in a particular place at the same time. Population size – the number of individuals that the population contains.

addo
Download Presentation

Chapter 19-20

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 19-20 Populations and Species Interactions

  2. Properties of a Population • Population – a group of organisms that belong to the same species and live in a particular place at the same time. • Population size – the number of individuals that the population contains. • Size is fundamental and important to population • Population Density – measures how crowded a population is. • Human population density in America is 30 people per square kilometer. • Dispersion – spatial (3D) of individuals within a population • Clumped – individuals are clustered together • Uniform – separated by fairly consistent distance • Random – independent of others location

  3. Population Dynamics • Populations change over time. There are many different reasons or things to consider when looking at the change. • Birth rate • Death rate • Life Expectancy

  4. Population Growth Rate • Growth rate – the amount by which a population’s size changes in a given time. • The growth rate depends on: • Birth • Death • Emigration – movement of individuals out of the population • Immigration – movement of individuals into a population • Growth rate can be found by: Birth rate – death rate = growth rate

  5. Carrying Capacity • It is the number of individuals the environment can support over a long period of time.

  6. Population Regulation • Density – independent factors – reduce the population by the same proportion, regardless of the population’s size. • Floods, fire, weather • Density – dependent factors – an individual’s chance of surviving or reproducing depends on the number of individuals in the same area • Resource limitations: food shortage, nesting

  7. Species Interaction • Predation – an individual of one species, called the predator, eats all or part of an individual of another species call the prey. • Species adapt in order to avoid being prey. • EX: venom, heat sensitive pits, sense of smell = snake • EX: sticky webs of spiders • EX: Amazonian poison frog uses its bright skin to warn everyone it is poisonous • Mimicry – one species closely resembles another species

  8. Competition • Interspecific competition – type of interaction in which two or more species use the same limited resource. • EX: plants competing for sunlight • EX: Lions and hyenas compete for zebra’s as food • Competitive Exclusion – situation where on species is eliminated from a community because of competition • Reduced niche size – can cause inter species competition

  9. Symbiosis • Symbiosis – close, long-term relationship between two organisms. • Three types: • Parasitism – one individual is harmed, one benefits • Mutualism – both benefit • Commensalism - one individual benefits, one is unaffected

  10. Succession • Primary Succession – development of a community in an area that has no life forms • Pioneer species – 1st to in habit the area • Secondary Succession – development of a community in an area that has been damaged, but still has life form

More Related